The present invention relates to transmission of,—or preparation, for transmission, of—an access unit stream such as a stream of media, such as video, audio, text or other data, access units. In some embodiments, the transmission involves the transmission of video access units via an audio broadcast signal, such as DRM.
There are many transmission capabilities especially dedicated for the transmission of specific kinds of data such as video and audio data, respectively. For example, DVB-T has been designed to broadcast video data. DRM, in turn, was designed to reach, via audio content, audiences scattered over a wide geographical area in order to keep citizens living abroad informed and up-to-date about what is going on in the home country, for example. Whatever transmission capability is considered, the design parameters of these transmission capabilities, such as maximum bandwidth for the useful data, the number of channels or programs being supported and the performance in terms of adjusting the bandwidth distribution among the supported channels or programs, is configured to fit to the demands posed by the specific form of data for which the respective transmission capability has been designed. For example, audio content needs less bandwidth than video content. Moreover, the error tolerances are different. Some of the transmission capabilities are dedicated for being transmitted via physical layers which, per se, have a limited bandwidth capability. DRM, for example, was originally designed to be transmitted in the bands allowing larger broadcast distances with, however, accepting limited bandwidth capabilities resulting therefrom.
Based on the transmission capabilities being available so far, there is a need for a transmission concept or for a transmission preparation concept which enables the transmission of an access unit stream via some existing transmission capability which has, for example, not been designed to transmit such access unit stream in terms of bandwidth, for example. Consider, for example, attempting to provide a video transmission service within a transmission capability such as within the DRM structure. DRM transmits the useful data at relatively low bandwidth when considering video content needs and using bursts at a considerable burst pitch. In such a situation, a considerable time delay would result when switching from one program to the just-mentioned video content, during which, at the decoding side, the decoder would not even have the capability to synchronize into the video content.